1. Field of the Invention
The present invention relates to novel compounds having both diuretic and antihypertensive actions, more particularly it relates to 2,3-dihydrobenzofuran-5-sulfonamide derivatives, having remarkable both diuretic and antihypertensive actions with the effect of excretion of uric acid, and to the diuretic antihypertensives containing them.
2. Prior Art
All diuretic antihypertensives are classified, by the actions and the structures thereof, to diuretic thiazides, loop diuretics, and potassium-sparing diuretics such as antialdosterone-type compounds. The dihydrobenzofuransulfonamide derivatives of the present invention can be reasonably classified to loop diuretics. Followings are the representative of loop diuretic agents which are clinically used or are under research and development.
Ethacrynic acid: Edecril.RTM. (Nippon Merck-Banyu), PA1 Chlorthialidone: Hygroton.RTM. (Fujisawa Pharmaceutical Co., Ltd./Ciba-Geigy Japan), PA1 Mefruside: Baycaron.RTM. (Yositomi Pharmaceutical Ind.) PA1 Furosemide: Lasix.RTM. (Hoechst) PA1 Bumetanide: Lunetoron.RTM. (Sankyo Co., Ltd.) PA1 Tienilic acid, or Ticrynafen: U.S. Pat. No. 3,758,506 (C.E.R.P.H.A.), l PA1 Indacrinone and the relates: Japanese Unexamined Patent Publication Nos. 57-163338, 57-163339, 57-176920, 57-176968, 57-209246 Merck), PA1 Benzenesulfonamide derivatives substituted at 2, 3, and 4 positions: JPN Unexam. Pub. No. 58-124758 (Fujisawa Pharmaceutical Co., Ltd.), PA1 5-Acyl-substituted-2,3-dihydrobenzofuran derivatives: JPN Unexam. Pub. No. 52-10261 (Merck). PA1 R.sup.1 and R.sup.2 may cyclize together with the adjacent nitrogen atom to form a substituted or unsubstituted 5- or 6-membered hetero cycle which may have additional one or more hetero atoms, PA1 R.sup.3 is a group represented by COR.sup.4 or CH.sub.2 R.sup.5, PA1 R.sup.4 is hydroxy or a group represented by OR.sup.6 or NR.sup.7 R.sup.8, PA1 R.sup.5 is hydroxy, lower alkoxy, lower aliphatic acyloxy, or halogen, PA1 R.sup.6 is lower alkyl, aryl, carboxymethyl or an ester thereof, hydroxymethyl or an aliphatic acylate thereof, or 3-phthalidyl, PA1 R.sup.7 and R.sup.8, which are the same or different each other, each is hydrogen or lower alkyl, and PA1 X and X', which are the same or different each other, each is hydrogen or halogen.
The compounds of this invention are classified to the same family as the compounds finally listed above, i.e., 5-Acyl-substituted-2,3-dihydrobenzofuran derivatives, in their essential structure, but different in their partial structure, i.e., the latter is 5-acyl compound, while the former is sulfonamide one.